I'm so frigging annoyed, wrote the longest answer and is disappeared on me when I pressed preview :@ So here's a quicker less detailed version:
For your face pluck your eyebrows in a nice fashion and use a brow highligher and color takes very little time with big pay-off. Here's a good product link and here's a good tutorial for explaining how to use them link (he's awesome with everyday makeup so watch the rest of his videos if you're interested)
For hair, use mousse applied from roots and down to the rest if you've thin, flat hair. Bigger and/or frizzy and/or long hair often needs a few drops of oil on the tips. You can do expensive argan oil or cheap vegetable cooking oil with almost the same result (just don't take cooking oil that smells bad!).
A pair of tiny earrings that you use everyday looks stylish without effort and lasts long, think something this size or even smaller link
Clothing is hard to give advice on without knowing anything about your or where you live, but in general spend WAY more on outerwear than inner. A well matched jacket, shoes and & bag/rucksack/whatever-works-for-you gives a very nice first impression. Expensive shoes are so much more price effective than cheaper. A pair of $70-100 shoes can loot stylish for YEARS if you care for them properly (sales assistant can tell you how), while $10 shoes will probably look nice for five minutes, hurt your feet and then break. And then you'll have to look for another pair that matches your outfit. For all your outerwear think good FIT, looks CLEAN, not WORN DOWN (unless perhaps shoes, some look better worn) and MATCHES well with the rest.
Simply take a bath everyday, and wear very nice, and comfortable clothes.
Just do what you're doing, but do it everyday...it's not that difficult, you just have to be willing to put in the time is all. Most women who don't look put together everyday, don't put the time in to it
I find its hard to look wonderfull without much money. But you still could wash your hair and shower every day and for clothes go to the outlets or something. I don't know where you live but I have found that Nordstrom rack has great buys 200 top I got for 20 bucks you can't beat that.
I only make a real effort to look of when I'm leaving the apartment but when I do leave, I make see I look good. It's not hard to look good every day, you just need to shower every morning and evening, eat healthily ( no oily foods), and you can get this vitamins called skinhairnails and they basically make your skin glow more, your hair shinier and smoother and your nails shiny
I think I look pretty polished everyday,and I do it by making sure my hair is on point,my makeup is on point,teeth are white,and I keep my nails painted.
Take good care of your skin and hair, getting cheap trims whenever your hair starts looking a bit dull. If your funds are too low, go for runs instead of the gym or the pool.
Nobody expects expensive clothing, just keep it tidy and make sure things fit you properly - a good silhouette is subtle, but more important than flashy style, IMO. If you are talking about work clothing, a few good quality skirts and pants are a must, then you can alternate between cheap blouses.
Not sure if this is what you meant, but this is how I got through uni with a part time job, while paying rent.